I was able to purchase a D4 on Friday from a NPD store about 1 hour from Cleveland without pre-ordering. So, if you're still looking for a D4 (and you didn't pre-order), you might consider searching in smaller cities (that have NPD -Nikon Professional Dealer- stores) in the vicinity of medium-sized or larger cities.
The NPD stores in Cleveland and Pittsburgh both demanded deposits for the privilege of pre-ordering a D4.
In case you were wondering, the D4 came with the Sony XQD memory card and reader, and I doubt if you can buy them anywhere at this point. My research showed that they're pre-order items.
If you're willing to tempt fate, Bestbuy's website will sell the D4 whenever they arrive and they don't accept pre-orders.
I might have posted this in the wrong forum. If the post can be moved, that would be great.